Turbine engines, and particularly gas or combustion turbine engines, are rotary engines that extract energy from a flow of combusted gases passing through the engine onto a multitude of turbine blades. Gas turbine engines have been used for land and nautical locomotion and power generation, but are most commonly used for aeronautical applications such as for aircraft, including helicopters. In aircraft, gas turbine engines are used for propulsion of the aircraft. In terrestrial applications, turbine engines are often used for power generation.
Gas turbine engines for aircraft are designed to operate at high temperatures to maximize engine efficiency. Temperatures in the high pressure turbine are around 1000° C. to 2000° C. and fluid from the compressor is around 500° C. to 760° C. Internal components of gas and steam turbines, for example, steam turbine blades are typically visually inspected, during a turbine outage, by inserting a borescope through an opening in the outer turbine shell and articulating the video head of the borescope to achieve the desired inspection view. Typically a waiting period is necessary after shutdown and before inspection because current borescope inspection equipment has a temperature limit of approximately 50° C. As a result of this temperature limitation, gas and steam turbine inspections cannot be performed until the turbine cools down from its normal operating temperature.